Using high-performance liquid chromatography were qualitatively and quantitatively identified high fatty acids contained in grape seed oil and compare its biological activity as 1,0% and 2,5% food-additive an fatty acids composition contained in lipids of mice livers. Investigation were carried out on 90 inbred mice 5,0 g weight. Using high-performance liquid chromatography methods in grape seed oil is identified linoleic (65,0%), linolenic (1,5%), oleic (17,0%), palmitic (8,0%), stearic (4,4%) and arachidonic (0,6%) acids. After 15 days fatty acids are carried out from mouse liver and individual identified. In paper is showed that 1,0% and 2,5% grape seed oil food-additive have a different biological activity. The investigation demonstrated that after 15 days the grape seed oil takes marked part in lipid metabolism of biological necessary components.